Philips TEA1064A-C2, TEA1064A-C1, TEA1064AT-C2, TEA1064AT-C1 Datasheet

DATA SH EET

Product specification
File under Integrated Circuits, IC03A

March 1994

INTEGRATED CIRCUITS

TEA1064A

Low voltage versatile telephone
transmission circuit with dialler
interface and transmit level
dynamic limiting

March 1994 2

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

GENERAL DESCRIPTION

The TEA1064A is a bipolar integrated circuit that performs
all the speech and line interface functions required in fully
electronic telephone sets. It performs electronic switching
between dialling and speech and has a powerful DC
supply for peripheral circuits. The IC operates at line
voltages down to 1.8 V DC (with reduced performance) to
facilitate the use of more telephone sets connected in
parallel. The transmit signal on the line is dynamically
limited (speech-controlled) to prevent distortion at high
transmit levels of both the sending signal and the sidetone.

FEA TURES

• Low DC line voltage; operates down to 1.8 V (excluding
polarity guard)

• Voltage regulator with low voltage drop and adjustable
static resistance

• DC line voltage adjustment facility

• Provides a supply for external circuits in two options:

unregulated supply, regulated line voltage;
stabilized supply, line voltage varies with supply

current

• Dynamic limiting (speech-controlled) in transmit
direction prevents distortion of line signal and sidetone

• Symmetrical high-impedance inputs (64 kΩ) for
dynamic, magnetic or piezo-electric microphones

• Asymmetrical high-impedance input (32 kΩ) for electret
microphones

• DTMF signal input

• Confidence tone in the earpiece during DTMF dialling

• Mute input for disabling speech during pulse or DTMF

dialling

• Power-down input for improved performance during
pulse dial or register recall (flash)

• Receiving amplifier for magnetic, dynamic or
piezo-electric earpieces

• Large amplification setting ranges on microphone and
earpiece amplifiers

• Line loss compensation (line current dependent) for
microphone and earpiece amplifiers (not used for DTMF
amplifier)

• Gain control curve adaptable to exchange supply

• Automatic disabling of the DTMF amplifier in

extremely-low voltage conditions

• Microphone MUTE function available with switch

PACKAGE OUTLINES

Notes

1. SOT146-1; 1998 Jun 18.

2. SOT163-1; 1998 Jun 18.

TEA1064A :20-lead DIL; plastic (SOT146).

(1)

TEA1064AT:20-lead mini-pack; plastic (SO20;
SOT163A).

(2)

March 1994 3

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

Fig.1 Block diagram.

handbook, full pagewidth

+

MGR056

CURRENT

REFERENCE

START

CIRCUIT

DYNAMIC

LIMITER

LOW

VOLTAGE

CIRCUIT

AGC

CIRCUIT

SUPPLY AND
REFERENCE

1711

V

EE

REG AGC STAB

DLS/MMUTE

SLPE

GAS2

GAS1

QR−

QR+

GAR

LN

V

CC1

15

14

12

dB

8

9

+

−

+

−

18 10 7 20

13

IR

MIC+
MIC−

DTMF

MUTE

PD

+

−

+

−

−

116

TEA1064A

6

5
4

2

V

CC2

19

3

March 1994 4

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

QUICK REFERENCE DATA

PARAMETER CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

Operating ambient temperature
range T

amb

−25 −+75 °C

Line current operating range:

normal operation l

line

11 − 140

(1)

mA

with reduced performance l

line

2 − 11 mA

Internal supply current:

power-down input LOW V

CC1

= 2.8 V I

CC1

− 1.3 1.6 mA

power-down input HIGH V

CC1

= 2.8 V I

CC1

− 60 82 µA

Voltage gain range:

microphone amplifier G

v

44 − 52 dB

receiving amplifier G

v

20 − 45 dB

Line loss compensation:

gain control range G

v

5.7 6.1 6.5 dB
exchange supply voltage
range V

exch

36 − 60 V
exchange feeding bridge
resistance range R

exch

400 − 1000 Ω

Maximum output voltage swing

on LN (peak-to-peak value) R15 + R16 = 448 Ω

l

line

=15mA

I

p

= 2 mA V

LN(p-p)

3.7 3.95 4.2 V

I

p

= 4 mA V

LN(p-p)

3.0 3.25 3.5 V

Regulated line voltage application

R15 = 0 Ω;
R16 = 392 Ω

Supply for peripherals l

line

=15mA

I

p

= 1.4 mA V

p

2.5 −−V

I

p

= 2.7 mA;

R

REG-SLPE

=20kΩ V

p

2.9 −−V

DC line voltage l

line

=15mA

without R

REG-SLPE

V

LN

− 3.57 − V

R

REG-SLPE

=20kΩ V

LN

− 4.57 − V

March 1994 5

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

Note

1. For TEA1064AT the maximum line current depends on the heat dissipating qualities of the mounted device.

Stabilized supply voltage application

R15 = 392 Ω;
R16 = 56 Ω

Supply for peripherals l

line

= 15 mA

I

p

= 0 to 4 mA V

CC2-SLPE

3.05 3.3 3.55 V

DC line voltage l

line

=15mA

I

p

= 2 mA V

LN

4.2 4.4 4.8 V

I

p

= 4 mA V

LN

4.9 5.1 5.5 V

PARAMETER CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

PINNING

Fig.2 Pinning diagram.

handbook, halfpage

LN
GAS1
GAS2

QR−
QR+

GAR

DLS/MMUTE

MIC−
MIC+

STAB

SLPE
V

CC2

AGC
REG

PD
MUTE

V

CC1

IR
DTMF
V

EE

1
2
3
4
5
6
7
8
9

10

11

12

20
19
18
17
16
15
14
13

TEA1064A

MGR057

1 LN positive line terminal
2 GAS1 gain adjustment; transmitting amplifier
3 GAS2 gain adjustment; transmitting amplifier
4QR− inverting output, receiving amplifier
5QR+ non-inverting output, receiving

amplifier
6 GAR gain adjustment; receiving amplifier
7 DLS/

MMUTE

decoupling for transmit amplifier

dynamic and microphone MUTE input
8 MIC− inverting microphone input
9 MIC+ non-inverting microphone input

10 STAB current stabilizer

11 V

EE

negative line terminal

12 DTMF dual-tone multi-frequency input
13 IR receiving amplifier input
14 MUTE mute input
15 PD power-down input
16 V

CC1

internal supply decoupling

17 REG voltage regulator decoupling
18 AGC automatic gain control input
19 V

CC2

reference voltage with respect to SLPE

20 SLPE slope adjustment for DC

curve/reference for peripheral circuits.

March 1994 6

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

FUNCTIONAL DESCRIPTION
Supplies V

CC1

, V

CC2

, LN, SLPE, REG and STAB (Fig.3)

Power for the TEA1064A and its peripheral circuits is
usually obtained from the telephone line. The IC develops
its own supply voltage at V

CC1

and regulates its voltage
drop. The internal supply requires a decoupling capacitor
between V

CC1

and VEE. The internal current stabilizer is

set by a 3.6 kΩ resistor between STAB and VEE.
The DC current flowing into the set is determined by the

exchange supply voltage V

exch

, the feeding bridge

resistance R

exch

, the subscriber line DC resistance R

line

and the DC voltage (including polarity guard) on the
subscriber set (see Fig.3).

The internal voltage regulator generates a
temperature-compensated reference voltage that is
available between V

CC2

and SLPE

[V

ref=VCC2-SLPE

= 3.3 V (typ.)]. This internal voltage
regulator requires decoupling by a capacitor between REG
and VEE(C3).

The reference voltage can be used to:

• regulate directly the line voltage (stabilized
V

LN-SLPE=VCC2-SLPE

)

(1)

• to stabilize the supply voltage for peripherals.

Regulated line voltage

In this application the V

CC2

pin is connected to the LN pin
as shown in Fig.3. This configuration gives a stabilized
voltage across pins LN and SLPE which, applied via the
low-pass filter R16, C15, provides a supply to the
peripherals that is independent of the line current and
depends only on the peripheral supply current.

The value of R16 and the level of the DC voltage V

LN-SLPE

determine the supply capabilities. In the basic application
R16 = 392 Ω and C15 = 220 µF. The worst-case
peripheral supply current as a function of supply voltage is
shown in Fig.4. To increase the supply capabilities, the DC
voltage V

LN-SLPE

can be increased by using R

VA(REG-SLPE)

or by decreasing the value of R16.

(1) The TEA1064A application with regulated line voltage is the

same as is used for TEA1060/TEA1061, TEA1067 and
TEA1068 integrated circuits.

Fig.3 Application with regulated line voltage (stabilized V

LN-SLPE

).

The voltage V

LN-SLPE

is fixed to V

ref

= 3.3± 0.25 V. Resistor R16 together with the
line current determine the supply capabilities and the maximum output swing on
the line (no loop damping is necessary).
The line voltage V

LN=Vref

+ ([I

line

− 1.55 mA]× R9).

handbook, full pagewidth

MGR058

R

exch

R

line

I

line

V

exch

DC
AC

17

REG

C3 R5

R9

10

STAB20SLPE

LN
1

V

CC1

16

19

V

CC2

11

V

EE

0.25 mA

R1

I

SLPE

I

CC1

R16C1

C15

peripheral

circuits

V

p

I

p

TEA1064A

Ip + 0.25 mA

March 1994 7

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

The maximum AC output swing on the line at low line
currents is influenced by R16 (limited by current) and the
maximum output swing on the line at high line currents is
influenced by the DC voltage V

LN-SLPE

(limited by voltage).
In both these situations, the internal dynamic limiter in the
sending channel prevents distortion when the microphone
input is overdriven. The maximum AC output swing on LN
is shown in Fig.5; practical values for R16 are from 200 to
600 Ω and this influences both the maximum output swing
at low line currents and the supply capabilities.

The SLPE pin is the ground reference for peripheral
circuits, therefore inputs MUTE, PD and DTMF are also
referenced to SLPE.

Active microphones can be supplied between V

CC1

and
VEE. Low-power circuits that provide only MUTE and/or PD
inputs to the TEA1064A also can be powered from V

CC1

.

However V

CC1

cannot be used for circuits that provide

DTMF signals to the TEA1064A because V

CC1

is referred

to ground.
If the line current l

line

exceeds I

CC1

+ 0.25 mA, the voltage
converter shunts the excess current to SLPE via LN;
where I

CC1

≈ 1.3 mA, the value required by the IC for

normal operation.

Fig.4 Minimum supply current for peripherals (Ip)

as a function of the peripheral supply
voltage (Vp).

handbook, halfpage

2

5

0

1

MGR059

2

3

4

34

V

p

(V)

I

p

(mA)

R

VA (REG-SLPE)

= 20 kΩ

without

R

VA (REG-SLPE)

l

line

= 15mA; R16 = 392Ω; R15 = 0 Ω; valid for MUTE = 0 and 1.

Line current has very little influence

The DC line voltage on LN is:

VLN=V

LN-SLPE

+ (I

SLPE

× R9)

VLN=V

ref

+ ([I

line

− I

CC1

− 0.25 × 10−3A] × R9)

in which

V

ref

= 3.3 V ± 0.25 V is the internal reference voltage

between V

CC2

and SLPE; its value can be adjusted by

external resistor R

VA

R9 = external resistor between SLPE and VEE(20 Ω in
basic application).

With R9 = 20 Ω, this results in:

VLN= 3.57 ± 0.25 V at l

line

=15mA

VLN= 4.17 ± 0.3 V at l

line

=15mA,

R

VA(REG-SLPE)

=33kΩ

VLN= 4.57 ± 0.35 V at l

line

= 15 mA,

R

VA(REG-SLPE)

=20kΩ

The preferred value for R9 is 20 Ω. Changing R9
influences microphone gain, DTMF gain, the gain control
characteristics, sidetone, and the DC characteristics
(especially the low voltage characteristics).

In normal conditions, I

SLPE

>> (I

CC1

+ 0.25 mA) and the
static behaviour is equivalent to a voltage regulator diode
with an internal resistance of R9. In the audio frequency
range the dynamic impedance is determined mainly by R1.
The equivalent impedance of the circuit in the audio
frequency range is shown in Fig.6.

The internal reference voltage V

CC2-SLPE

can be increased

by external resistor R

VA(REG-SLPE)

connected between

REG and SLPE. The supply voltage V

CC2-SLPE

is shown as

a function of R

VA(REG-SLPE)

in Fig.7. Changing the
reference voltage influences the output swing of both
sending and receiving amplifiers.

At line currents below 8 mA (typ.), the DC voltage dropped
across the circuit is adjusted to a lower level automatically
(approximately 1.8 V at 2 mA). This gives the possibility of
operating more telephone sets in parallel with DC line
voltages (excluding polarity guard) down to an absolute
minimum of 1.8 V. At line currents below 8 mA (typ.), the
circuit has limited sending and receiving levels.

March 1994 8

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

Fig.5 Maximum AC output swing on the line as a

function of line current with peripheral
supply current as a parameter: R15 = 0 Ω;
R16 = 392 Ω.

handbook, halfpage

10

6

4

2

0

20 30

MGR060

I

line

(mA)

V

LN(p-p)

(V)

Ip =
0 mA

2 mA
4 mA

Fig.6 Equivalent impedance between LN and

VEEin the application with stabilized
V

LN-SLPE

:
R15 = 0 Ω
Leq=C3×R9 × R

p

Rp=15kΩ

handbook, halfpage

MGR061

R9
20 Ω

REG

LN

C3

4.7 µF

R

p

V

ref

L

eq

V

CC1

V

EE

C1

R1

Fig.7 Internal reference voltage V

CC2-SLPE

as a function of resistor R

VA(REG-SLPE)

for line currents between 11

and 140 mA.

In the stabilized supply application:

VLN=V

CC2-SLPE

+ ([Ip+ 0.25 × 10−3A] × R15) + ([I

line

− 1.55 × 10−3A] × R9)

In the unregulated supply application (R15 = 0 Ω):

VLN=V

CC2-SLPE

+ ([I

line

− 1.55 × 10−3A] × R9)

handbook, full pagewidth

7.8

3.0
08040 120

MGR062

4.2

5.4

6.6

RVA (REG-SLPE) (kΩ)

V

ref

(V)

with R

VA

infinite

March 1994 9

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

Stabilized peripheral supply voltage

The configuration shown in Fig.8 provides a stabilized
voltage across pins V

CC2

and SLPE for peripheral circuits
(such as dialling and control circuits); the DC voltage
VLNnow varies with the peripheral supply current.

The V

CC2-SLPE

supply must be decoupled by capacitor
C15. For stable loop operation, resistor R16 (≈ 50 Ω) is
connected between V

CC2

and SLPE in series with C15.
The voltage regulator control loop is completed by resistor
R15 between LN and V

CC2

.

For sets with an impedance of 600 Ω, practical values are:
R15 = 200 to 600 Ω; C15 = 220 µF; C3 = 470 nF. The
ratio R15/R16 ≤ 8 is for stable loop operation with
sufficient phase margin, and R15/R16 ≥ 6 is for
satisfactory set impedance in the audio frequency range.

For sets with complex impedance, the value of C3 and the
ratio R15/R16 are different (further information is given in
the TEA1064A Application Report

(1)

).

The peripheral supply capability depends mainly on the
available line current, the required AC output swing on the
line, the maximum permitted DC voltage on the line and

the values of external components (especially R15). With
R15 = 392 Ω and R16 = 56 Ω (basic application) the
maximum possible AC output swing on the line as a
function of line current is as shown in Fig.9, the curve
parameter is the peripheral supply current (Ip). Different
values for R15 (from 200 to 600 Ω) maintaining
6 < R15/R16 < 8 give different results (these are described
in the TEA1064A Application Report

(1)

.

(1) Supplied on request.

Fig.8 Application with stabilized supply voltage for peripheral circuits: R15 = 392 Ω; R16 = 56 Ω.

handbook, full pagewidth

MGR063

R

exch

R

line

I

line

V

exch

DC
AC

17

REG

C3 R5

R9

10

STAB20SLPE

LN
1

V

CC1

16

19

V

CC2

11
V

EE

0.25 mA

R1

R15

I

SLPE

I

CC1

R16C1

C15

peripheral

circuits

V

p

I

p

TEA1064A

Ip + 0.25 mA

March 1994 10

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

The DC line voltage on LN is

VLN=V

LN-SLPE

+ (I

SLPE

× R9).

Therefore

VLN=V

ref

+ ([Ip+ 0.25 × 10−3A] × R15) +

([l

line

− I

CC1

− 0.25 × 10−3A] × R9)

in which:

V

ref

is the internal reference voltage between V

CC2

and

SLPE (the value of V

ref

can be adjusted by an external

resistor, RVA). V

ref

= 3.3 V (typ.) without R

VA

Ipis the supply current used by peripheral circuits
R15 is an external resistor between LN and V

CC2

(392 Ω

in the basic application)
R9 is an external resistor between SLPE and

VEE(20 Ω in the basic application)

The DC voltage V

LN-SLPE

as a function of Ipwith R15 as a
parameter is shown in Fig.10. In the audio frequency
range, the dynamic impedance is determined mainly by
R1. The equivalent impedance in the audio range of the
circuit (Fig.8) is shown in Fig.11.

Fig.9 Maximum output swing on line as a function

of line current with the peripheral supply
current as a parameter; R15 = 392 Ω;
R16 = 56 Ω.

As different values of R15 and R16 are allowed, different curves
would then apply

handbook, halfpage

10

8

4

6

2

0

20 30

MGR064

I

line

(mA)

V

LN(p-p)

(V)

Ip = 4 mA

2 mA

0 mA

Fig.10 Curves showing the typical voltage drop

between LN and SLPE as a function of the
supply current for peripherals with R15 as a
parameter: V

CC2-SLPE

= 3.3 V (RVAnot

connected).

V

CC2-SLPE

can be adjusted between approximately 3.3 and 4.3 V by

changing the value of R

VA

, this results in a parallel-shift of the curves.

The total voltage drop V

LN

≈ V

LN-SLPE

+ ([I

line

− 1.55 mA] × R9).

handbook, halfpage

012 4

5.5

3.0

5.0

MGR065

3

4.0

4.5

3.5

Ip (mA)

V

LN-SLPE

(V)

R15 = 511 Ω

392 Ω

301 Ω

Fig.11 Equivalent impedance between LN and

VEEat f > 300 Hz in the application with
stabilized supply voltage for peripheral
circuits.

ReqR

p

R15
R16

----------- 1+





=

LeqC3 R9× Reqwith Rp15 kΩ=×=

handbook, halfpage

MGR066

R9
20 Ω

LN

C3
470 nF

R

eq

L

eq

V

EE

R1
620 Ω

March 1994 11

Philips Semiconductors Product specification

Low voltage versatile telephone transmission circuit
with dialler interface and transmit level dynamic limiting

TEA1064A

Microphone inputs MIC+ and MIC− and gain pins
GAS1 and GAS2

The TEA1064A has symmetrical microphone inputs, its
input impedance is 64 kΩ (2 × 32 kΩ) and its voltage
amplification is typ. 52 dB with R7 = 68 kΩ. Either
dynamic, magnetic or piezo-electric microphones can be
used, or an electret microphone with a built-in FET buffer.
Arrangements for the microphone types are shown in
Fig.12.

The gain of the microphone amplifier is proportional to
external resistor R7 connected between GAS1 and GAS2
and with this it can be adjusted between 44 dB and 52 dB
to suit the sensitivity of the transducer.

An external 100 pF capacitor (C6) is required between
GAS1 and SLPE to ensure stability. A larger value of C6
may be chosen to obtain a first-order low-pass filter with a
cut-off frequency corresponding to the time constant
R7 × C6.

Fig.12 Microphone arrangements: a) magnetic or dynamic microphone, the resistor (1) may be connected to

reduce the terminating impedance, or for sensitive types a resistive attenuator can be used to prevent
overloading the microphone inputs; b) electret microphone; c) piezo-electric microphone.

handbook, full pagewidth

MGR067

V

EE

V

CC1

16

8

9

11

9

8

(1)

(a) (b)

(c)

MIC+

MIC−

MIC−

MIC+

9

8

MIC−

MIC+

Dynamic limiter (microphone) pin DLS/MMUTE

A low level at the DLS/MMUTE pin inhibits the microphone
inputs MIC+ and MIC− but has no influence on the
receiving and DTMF amplifiers.
Removing the low level at the DLS/MMUTE pin provides
the normal function of the microphone amplifier after a
short time determined by the capacitor connected to
DLS/MMUTE pin. The microphone mute function can be
realised by a simple switch as shown in Fig.13.

To prevent distortion of the transmitted signal, the gain of
the sending amplifier is reduced rapidly when peaks of the
signal on the line exceed an internally-determined
threshold. The time in which gain reduction is effected
(attack time) is very short. The circuit stays in the
gain-reduced condition until the peaks of the sending
signal remain below the threshold level. The sending gain
then returns to normal after a time determined by the
capacitor connected to DLS/MMUTE (release time).

The internal threshold adapts automatically to the DC
voltage setting of the circuit (voltage V

LN-SLPE

). This

means that the maximum output swing on the line will be
higher if the DC voltage dropped across the circuit is
increased.

Fig.14 shows the maximum possible output swing on the
line as a function of the DC voltage drop (V

LN-SLPE

) with

I

line

− Ipas a parameter.

Fig.13 Microphone-mute function.

handbook, halfpage

MGR068

R17

3.3 kΩ

7

11

DLS/MMUTE

V

EE